The chimney swift (Chaetura pelagica) feeds primarily on flying insects, but also on airborne spiders. It generally mates for life. It builds a bracket nest of twigs and saliva stuck to a vertical surface, which is almost always a human-built structure, typically a chimney. The female lays 4–5 white eggs. The altricial young hatch after 19 days and fledge a month later. The average chimney swift lives 4.6 years.